Hyperfine interaction, Raman and magnetic study of YFeO3 nanocrystals

Glycine Nitrate Process (GNP) was used to obtain orthoferrites YFeO3 (YFO) nanoparticles. The structural phase formation of compound was confirmed by using XRD and Raman spectroscopy. Morphological, thermal, ferroelectric and magnetic properties at room temperature have been systematically studied via TEM, TG-DSC, Mossbauer, PE loop, and SQUID. Single phase YFeO3 nano-crystals with orthorhombic Pnma space group were successfully derived from GNP with average crystallite size 50-60 nm. The magnetic hysteresis loops indicates Fe spins orders antiferromagnetically with weak ferromagnetism due to the superexchange and Dzyaloshinski-Moriya (DM) antisymmetric exchange mechanism. The vibrational properties were characterized by Raman spectroscopy, in which 12 active modes were observed out of 24 Raman active modes. Spin-exchange striction is considered as a microscopic origin of ferroelectric polarization. The evidence for the ferroelectric character of the samples is observed in the saturation polarization loops at room temperature. Mossbauer spectra and XPS show that the Fe3+ is dominated in the compound.